Brass for 77 TMK AR15

[treillw]

Managed to get 1500 77 grain TMKs. Now I need brass to go along with them.

I want to load them up to shoot as hot as possible from a 10.5" and 14.5" AR.

I was going to buy bulk once fired Lake City brass (probably 3000), but there are so many inconsistencies in years, lots, etc, etc - probably not the best if you're running a max powder charge to have different case volumes.

The majority of the reloading that I have done in the past is for long range precision - measuring powder to the nearest kernel and seating bullets to +/- .0005". The idea of all the inconsistencies from 1500 pieces of brass wreaks havoc on my OCD, but at the same time I don't want to spend $$$$ on all Lapua brass.

I'd be happy if I can get them to shoot minute groups. The TMK is one of the best projectiles out there, and I don't want to "waste" them by using junk brass and creating poor reloads.

I will probably shoot 100 or so of the rounds to verify function and then store the rest away for a rainy day.

What brass would you use for them? Any good suppliers out there?

Thanks!

 

[Dogtown]

Out of a 10.5 & 14.5 inch AR? Don't overthink it and just use some reconditioned LC brass

.223 Rem Unprimed Reconditioned Brass 250pcs | Top Brass, Inc.

250 once-fired, 100% reconditioned & fully processed .223 Remington brass shell casings, mixed military head stamps 90% lake city produced from 5.56 NATO brass, ready for reloading

www.topbrass-inc.com

 

[3rd Monkey]

I agree with Dogtown. You can definitely get sub-minute from LC brass. Personally, I run Norma because I bought 1000rds pre-plandemic and it's consistent. Long as you anneal between sessions, you're golden for several times over per case.

 

[Bacarrat]

LC one of the best brass out there. That's all I pretty much use in the MK12s.

 

[treillw]

I agree with Dogtown. You can definitely get sub-minute from LC brass. Personally, I run Norma because I bought 1000rds pre-plandemic and it's consistent. Long as you anneal between sessions, you're golden for several times over per case.

Do you have to anneal it after every firing?

I haven't seen any calibers which require that.

 

[Sogan]

Where are you all getting your LC brass at? Link above?

 

[3rd Monkey]

Do you have to anneal it after every firing?

I haven't seen any calibers which require that.

If you're loading it hot, I would. Not because of case splitting, but because of consistent neck tension and brass flow. I find it helps... may not be necessary.

 

[nn8734]

For your application, LC is more than sufficient. I wouldn’t bother spending any money on premium brass for carbines, juice is not worth the squeeze.

You need to balance cost, performance and reliability with your load component choices, equipment and development process. Don’t get hung up on one thing at the expense of other considerations.

Annealing after every firing provides max brass consistency between each firing and helps with brass life, especially if you’re loading to pressure.

Can i assume you will be seeking advice on primers next or are you squared away there?

 

[Ndbowhunter]

i went down this rabbit hole last winter

i don't think that 77gr tmk is the most accurate bullet you can run. especially if you want to run shit hot and have any kind of bulk reloading practices. it's probably a low 1.moa something 10 shot with LC brass and a mid 23gr load of 8208 or 24ish grains of rl-15 or varget.


the tmk advantage is it's terminal ballistics, and ability to cleave your velocity

you be a lot light years ahead to pick a medium load and run LC of the same weight if ur looking big picture.

it's still a gasser 223 and beyond 450 your potentially below minimum velocity of bullet upset. will a .9moa gun be sufficient but a 1.2moa not?

if money is no object lapua brass all day.

mid 23gr of 8208

cci 450

and fill an ark

as for Top brass (it can be junk) or annealing. i'd rather run it twice hot and dump then do insane case prep on something that hammers out the exhaust port a mag at a time.

 

[Ndbowhunter]

i quit sorting LC brass when i shot side by side steel with my go to load at 500 in mixed head stamp never annealed brass

and my sorted, same lot, annealed brass.

the different was so marginal it didn't warrant the time expenditure. about 1 moa vertical, a bit more on the horizontal.

and if ur gonna waste ur time to make good ammo and then let it sit for ages, the neck tension is going to go to shit anyways.

 

[Baddog 0302]

I want to load them up to shoot as hot as possible from a 10.5" and 14.5" AR.
At what distances are you planning on shooting these "barn burners" loads from your shorty AR's ?

 

[redbullitt]

Lc does great for me and the price is right. use it if you can get it.

Most of mine does seem to benefit from annealing, but not necessary. Bolt gun for the varmints here will shoot great using prepped lc brass... no issues at all.

In a carbine youll like it just fine. Be picky about it if you want with annealing, sorting, prepping etc. Not necessary, but can help if youre not happy with your lot of it.

Personally i clean and chamfer or swage if needed and feed it to the mk12 and sbr most of the time. No complaints.

 

[treillw]

For your application, LC is more than sufficient. I wouldn’t bother spending any money on premium brass for carbines, juice is not worth the squeeze.

You need to balance cost, performance and reliability with your load component choices, equipment and development process. Don’t get hung up on one thing at the expense of other considerations.

Annealing after every firing provides max brass consistency between each firing and helps with brass life, especially if you’re loading to pressure.

Can i assume you will be seeking advice on primers next or are you squared away there?

I'm always up for a little primer advice if you're selling haha

 

[treillw]

i quit sorting LC brass when i shot side by side steel with my go to load at 500 in mixed head stamp never annealed brass

and my sorted, same lot, annealed brass.

the different was so marginal it didn't warrant the time expenditure. about 1 moa vertical, a bit more on the horizontal.

and if ur gonna waste ur time to make good ammo and then let it sit for ages, the neck tension is going to go to shit anyways.

What happens with the neck tension?

 

[treillw]

I want to load them up to shoot as hot as possible from a 10.5" and 14.5" AR.
At what distances are you planning on shooting these "barn burners" loads from your shorty AR's ?

1250

 

[3rd Monkey]

I want to load them up to shoot as hot as possible from a 10.5" and 14.5" AR.
At what distances are you planning on shooting these "barn burners" loads from your shorty AR's ?

Pretty sure it's SHTF ammo, judging by bullet selection and the fact he says he precision loads... probably means he has a precision gun.

 

[3rd Monkey]

1250

That's a joke... right?

 

[nn8734]

I'm always up for a little primer advice if you're selling haha

I like Remington 7-1/2s for velocity however F205s have given me more consistent mvs in my mk12…For a carbine, it just comes down to what you can get your hands on in quantity, with some exceptions:

I understand winchester srp primer cups to be a little on the thin side so probably wouldn’t run them. Also no Remington 6-1/2s or cci400s (cup too thin)

Here’s more information: https://www.snipershide.com/shooting/threads/a-primer-on-primers.6936610/

 

[treillw]

That's a joke... right?

Why would you think it's a joke?? My buddy won a couple 1000 yards tournaments with the 223.





(Yes, it's a joke)

 

[3rd Monkey]

I like Remington 7-1/2s for velocity however F205s have given me more consistent mvs in my mk12…For a carbine, it just comes down to what you can get your hands on in quantity, with some exceptions:

I understand winchester srp primer cups to be a little on the thin side so probably wouldn’t run them. Also no Remington 6-1/2s or cci400s (cup too thin)

Here’s more information: https://www.snipershide.com/shooting/threads/a-primer-on-primers.6936610/

Agreed on the Rem 7 1/2s. Seem to get about 20-30 fps better, no matter the powder.

 

[3rd Monkey]

Why would you think it's a joke?? My buddy won a couple 1000 yards tournaments with the 223.





(Yes, it's a joke)

The intended purpose may net you better advice as to what you want to do.

 

[treillw]

The intended purpose may net you better advice as to what you want to do.

I want to shoot as far as I can.

The 10.5" should expand out to 300 yards with the tmk and I haven't done any math on the 14.5", but I'm not leaning towards ethical shot distances with an AR.

 

[3rd Monkey]

I want to shoot as far as I can.

The 10.5" should expand out to 300 yards with the tmk and I haven't done any math on the 14.5", but I'm not leaning towards ethical shot distances with an AR.

They don't have to be ethical to me... just count for something if sent.

 

[smoothy8500]

I'm gonna get some popcorn ready...

 

[Baddog 0302]

1250

He must have left off the inch's {"} sign.

 

[aklaunch]

Running an over gassed machine above design pressure, and with slow burning powders is asking for malfunctions.

I know in your first post you meant you wanted to run them as hot as you could, expecting 100% pure reliability.

It is true that you can get max velocity with some slower powders out of shorter barrels. Those powders will make your rifle run violently.

If you are a 1000 yard shooter, then you know about sticky bolts at pressure.

Reliability comes from smooth ejection, at the lowest port pressure you can create. You may be better off trading a few feet per minute for a cleaner, cooler burn temp coupled with reduced chamber pressure and reduced gas port pressure?

I have had a bunch of malfunctions on this quest. A pattern follows to those who pay attention.

All of the above stated problems are compounded if you have a dirty chamber.

Some brass you find will be very work hardened and spring back closer to the form it was before you sized it than others.

This will create possible chambering/head spacing problems.

Starline has 5.56 brass available for a short time every month or two. I have never tried it though. ( but i have some new brass waiting)

Once fired Lake City NATO brass is the Cats A$$ for semi autos.

So is Winchester brass.

 

[r.tenorio671]

...although cost and time sound like your higher priority/concerns, I think availability will be the greater obstacle. 1x LC or "NATO" certified brass will handle your intended "hot loads" better and most likely achieve an acceptable accuracy that can be expected out of your stated 10.5" & 14.5" barrels. Using a single brand of powder & primer in your final loads will give you a greater potential for consistency (and accuracy, regardless of FPS you finalize on). Your money, your time....make a decision and go with it.